Whotheguy

Okay guys, been lurking and now I have a problem I can't figure out.

2004 F150, 5.4, Code P0301, swapped coil with cyl 5, problem did not follow. Installed new Motorcraft coil anyhow, still crap. Using a screwdriver I can clearly hear the injector firing, ohm tested injector at 15.9, matches closely to 2 others I tested. Plugs were replaced 35k ago with Motorcraft. Pulled cyl 1 plug, looked fine, replaced plug with new Motorcraft one anyhow, cleared code and still runs like crap and code returns. I don't want to take the truck to the shop, I would rather fight through this, but I'm out of diag ideas. Oh, fuel filter was replaced 15k ago, again Motorcraft.

Thanks guys.

PerryB

Clogged injector maybe?

Whotheguy

I was thinking about replacing the injector as well to confirm. I got a new one delivered today, but don't have time yet. This thing is really stumping me.

DemShinyNutz

I'd check compression before throwing parts at it

Rexey

Check for coolant in the oil? Also intake manifolds are known to leak air. That would give you that poor running. Tried a compression test?